🔐 CVE Alert

CVE-2026-15243

UNKNOWN 0.0

Improper Validation of Certificate in CAS Client

CVSS Score
0.0
EPSS Score
0.0%
EPSS Percentile
0th

Apereo CAS Client accepts any CA-trusted certificate for any hostname, provided the URL the client is calling matches the configured allowlist or regex. An attacker with a MITM position (DNS poisoning, rogue Wi-Fi, malicious proxy, etc.) can provide any CA-signed certificate for a hostname that matches the configured allowlist or regex. This can lead to intercepting the CAS exchange, capturing the Ticket-Granting Ticket (TGT), and subsequently obtaining Service Tickets on behalf of the victim.  Because maintainers contact attempts were unsuccessful, vulnerabilities have only been confirmed in version 4.1.0 (Java Apereo CAS Client) and 3.6.4 (Jasig CAS Client) but may also affect other versions.

CWE CWE-297
Vendor apereo
Product java apereo cas client
Published Jul 24, 2026
Last Updated Jul 24, 2026
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Affected Versions

Apereo / Java Apereo CAS Client
4.1.0
Apereo / Jasig CAS Client
3.6.4

References

NVD ↗ CVE.org ↗ EPSS Data ↗
cert.pl: https://cert.pl/en/posts/2026/07/CVE-2026-15243 apereo.org: https://www.apereo.org/programs/software/cas

Credits

Rafał Łykowski (Qualtrics) Łukasz Kollbek (Qualtrics) Krzysztof Surówka (Qualtrics)